Remove old (dead) app list code.

ui/app_list/search_box_model.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_APP_LIST_SEARCH_BOX_MODEL_H_
 #define UI_APP_LIST_SEARCH_BOX_MODEL_H_
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "base/strings/string16.h"
@@ skipping 29 matching lines @@
     gfx::ImageSkia off_icon;
     base::string16 off_tooltip;
 
     // The accessibility name of the button.
     base::string16 accessible_name;
   };
 
   SearchBoxModel();
   ~SearchBoxModel();
 
-  // Sets/gets the icon on the left side of edit box.
-  void SetIcon(const gfx::ImageSkia& icon);
-  const gfx::ImageSkia& icon() const { return icon_; }
-
   // Sets/gets the properties for the button of speech recognition.
   void SetSpeechRecognitionButton(
       std::unique_ptr<SpeechButtonProperty> speech_button);
   const SpeechButtonProperty* speech_button() const {
     return speech_button_.get();
   }
 
   // Sets/gets the hint text to display when there is in input.
   void SetHintText(const base::string16& hint_text);
   const base::string16& hint_text() const { return hint_text_; }
 
   // Sets/gets the text for screen readers on the search box.
   void SetAccessibleName(const base::string16& accessible_name);
   const base::string16& accessible_name() const { return accessible_name_; }
 
   // Sets/gets the selection model for the search box's Textfield.
   void SetSelectionModel(const gfx::SelectionModel& sel);
   const gfx::SelectionModel& selection_model() const {
     return selection_model_;
   }
 
   // Sets/gets the text for the search box's Textfield.
   void SetText(const base::string16& text);
   const base::string16& text() const { return text_; }
 
   void AddObserver(SearchBoxModelObserver* observer);
   void RemoveObserver(SearchBoxModelObserver* observer);
 
  private:
-  gfx::ImageSkia icon_;
   std::unique_ptr<SpeechButtonProperty> speech_button_;
   base::string16 hint_text_;
   base::string16 accessible_name_;
   gfx::SelectionModel selection_model_;
   base::string16 text_;
 
   base::ObserverList<SearchBoxModelObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(SearchBoxModel);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_SEARCH_BOX_MODEL_H_